Error in test case

#1

i guess ther is some error in test case

#2

No I think testcases are working fine
because many other student also submitted the solution

which testcase you think is wrong??

#3

bro check -> ((a+(b))+(c+d)) it has duplicates

#4

in question this case is given as sample input and
and sample output is NOT DUPLICATATE
hence (b) it is not consider as duplicate because inside bracket b is present
((b)) this is dupicate

#5

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